service indicator GMC SIERRA DENALI 2018 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Introduction 3
Danger, Warning, and
Caution Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{ DangerDanger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{ WarningWarning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage. A circle with a slash through it is a
safety symbol which means “ Do
Not, ” “ Do not do this, ” or “ Do not let
this happen. ”
Symbols The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M : Shown when the owner ’ s
manual has additional instructions
or information.
* : Shown when the service
manual has additional instructions
or information.
0 : Shown when there is more
information on another page —
“ see page. ” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
9 : Airbag Readiness Light
# : Air Conditioning
! : Antilock Brake System (ABS)
$ : Brake System Warning Light
" : Charging System
I : Cruise Control
` : Do Not Puncture
^ : Do Not Service
B : Engine Coolant Temperature
O : Exterior Lamps
_ : Flame/Fire Prohibited
. : Fuel Gauge
+ : Fuses
3 : Headlamp High/Low-Beam
Changer
j : ISOFIX/LATCH System Child
Restraints

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 85
{ WarningIf the front outboard passenger
frontal airbag is turned off for a
person who is not in a risk group
identified by the national
government, that person will not
have the extra protection of an
airbag. In a crash, the airbag will
not be able to inflate and help
protect the person sitting there.
Do not turn off the front outboard
passenger frontal airbag unless
the person sitting there is in a risk
group. To turn off the front outboard
passenger frontal airbag, insert the
ignition key into the switch, push in,
and move the switch to the off
position.
The word OFF or the off symbol will
come on in the passenger airbag
status indicator located in the
overhead console to let you know
that the front outboard passenger
frontal airbag is off, after the system
check is completed. The airbag off
light will come on and stay on to let
you know that the front outboard
passenger frontal airbag is off. See
Airbag On-Off Light 0 147 . The front
outboard passenger airbag will
remain off until you turn it back on
again.
{ Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. For
example, the front outboard
(Continued) Warning (Continued) passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
To help avoid injury to yourself or
others, have the vehicle serviced
right away. See Airbag Readiness
Light 0 147 for more information,
including important safety
information.
To turn the front outboard passenger
frontal airbag on again, insert the
ignition key into the switch, push in,
and move the switch to the on
position.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
88 Seats and Restraints wear a seat belt properly — whether
or not there is an airbag for that
person.
{ WarningIf the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. See Airbag Readiness
Light 0 147 for more information,
including important safety
information.
If the On Indicator Is Lit for a
Child Restraint The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag if
the system determines that an infant
is present in a child restraint. If a
child restraint has been installed
and the on indicator is lit:
1. Turn the vehicle off. 2. Remove the child restraint from
the vehicle.
3. Remove any additional items
from the seat such as blankets,
cushions, seat covers, seat
heaters, or seat massagers.
4. Reinstall the child restraint
following the directions
provided by the child restraint
manufacturer and refer to
Securing Child Restraints (With
the Seat Belt in the Center
Front Seat) 0 114 or Securing
Child Restraints (With the Seat
Belt in the Front Passenger
Seat) 0 115 or Securing Child
Restraints (With the Seat Belt
in the Rear Seat) 0 111 .
Make sure the seat belt
retractor is locked by pulling
the shoulder belt all the way
out of the retractor when
installing the child restraint,
even if the child restraint is
equipped with a seat belt lock
off. When the retractor lock is
set, the belt can be tightened
but not pulled out of the
retractor. 5. If, after reinstalling the child
restraint and restarting the
vehicle, the on indicator is still
lit, turn the vehicle off. Then
slightly recline the vehicle
seatback and adjust the seat
cushion, if adjustable, to make
sure that the vehicle seatback
is not pushing the child
restraint into the seat cushion.
Also make sure the child
restraint is not trapped under
the vehicle head restraint.
If this happens, adjust the head
restraint. See Head Restraints
0 58 .
6. Restart the vehicle.
The passenger sensing system may
or may not turn off the airbag for a
child in a child restraint depending
upon the child ’ s size. It is better to
secure child restraints in the rear
seat. Consider using another
vehicle to transport the child when a
rear seat is not available. Never put
a rear-facing child restraint in the
front seat, even if the on indicator is
not lit.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
90 Seats and Restraints A thick layer of additional material,
such as a blanket or cushion,
or aftermarket equipment such as
seat covers, seat heaters, and seat
massagers can affect how well the
passenger sensing system
operates. We recommend that you
not use seat covers or other
aftermarket equipment except when
approved by GM for your specific
vehicle. See Adding Equipment to
the Airbag-Equipped Vehicle 0 90
for more information about
modifications that can affect how
the system operates.
The on indicator may be lit if an
object, such as a briefcase,
handbag, grocery bag, laptop,
or other electronic device, is put on
an unoccupied seat. If this is not
desired, remove the object from
the seat.
{ Warning
Stowing articles under the
passenger seat or between the
passenger seat cushion and
(Continued) Warning (Continued) seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle Airbags affect how the vehicle
should be serviced. There are parts
of the airbag system in several
places around the vehicle. Your
dealer and the service manual have
information about servicing the
vehicle and the airbag system. To
purchase a service manual, see
Service Publications Ordering
Information 0 474 .
{ Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
(Continued) Warning (Continued) are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly.
The operation of the airbag system
can also be affected by changing
any parts of the front seats, seat
belts, airbag sensing and diagnostic
module, steering wheel, instrument
panel, inner door seals including the
speakers, any of the airbag
modules, ceiling or pillar garnish

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
118 Seats and Restraints If a child restraint has been installed
and the on indicator is lit, see “ If the
On Indicator Is Lit for a Child
Restraint ” under Passenger Sensing
System 0 86 .
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
With Airbag On-Off Switch This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint 0 98 .
There may be a switch on the
instrument panel endcap that you
can use to turn off the front
outboard passenger frontal airbag.
See Airbag On-Off Switch 0 84 for
more information, including
important safety information.
Never put a rear-facing child
restraint in the front. This is because
the risk to the rear-facing child is so
great if the airbag deploys. { WarningA child in a rear-facing child
restraint can be seriously injured
or killed if the front outboard
passenger airbag inflates. This is
because the back of the
rear-facing child restraint would
be very close to the inflating
airbag. A child in a forward-facing
child restraint can be seriously
injured or killed if the front
outboard passenger airbag
inflates and the passenger seat is
in a forward position.
Even if the airbag switch has
turned off the front outboard
passenger frontal airbag, no
system is fail-safe. No one can
guarantee that an airbag will not
deploy under some unusual
circumstance, even though it is
turned off.
Secure rear-facing child restraints
in a rear seat, even if the airbag
is off. If you secure a
(Continued) Warning (Continued) forward-facing child restraint in
the front outboard passenger
seat, always move the seat as far
back as it will go. It is better to
secure the child restraint in a
rear seat.
{ WarningIf the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. For
example, the front outboard
passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
To help avoid injury to yourself or
others, have the vehicle serviced
right away. See Airbag Readiness
Light 0 147 for more information,
including important safety
information.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 137SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF
THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Warning Lights,
Gauges, and
Indicators Warning lights and gauges can
signal that something is wrong
before it becomes serious enough
to cause an expensive repair or
replacement. Paying attention to the
warning lights and gauges could
prevent injury. Some warning lights come on briefly
when the engine is started to
indicate they are working. When
one of the warning lights comes on
and stays on while driving, or when
one of the gauges shows there may
be a problem, check the section that
explains what to do. Waiting to do
repairs can be costly and even
dangerous.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 143When the ignition is on, the fuel
gauge indicates about how much
fuel is left in the tank.
There is an arrow near the fuel
gauge pointing to the side of the
vehicle the fuel door is on.
When the indicator nears empty, the
low fuel light comes on. There still is
a little fuel left, but the vehicle
should be refueled soon.
Here are four things that some
owners ask about. None of these
show a problem with the fuel gauge:
.
At the service station, the fuel
pump shuts off before the gauge
reads full.
.
It takes a little more or less fuel
to fill up than the gauge
indicated. For example, the
gauge may have indicated the
tank was half full, but it actually
took a little more or less than
half the tank's capacity to fill
the tank.
.
The gauge moves a little while
turning a corner or speeding up. .
The gauge takes a few seconds
to stabilize after the ignition is
turned on, and goes back to
empty when the ignition is
turned off.
Engine Oil Pressure
Gauge
Metric, Standard Theme Shown English, Standard Theme Shown
The engine oil pressure gauge
shows the engine oil pressure
in kPa (kilopascals) or psi (pounds
per square inch) when the engine is
running.
Oil pressure can vary with engine
speed, outside temperature, coolant
temperature, and oil viscosity.
A reading outside the normal
operating range can be caused by a
dangerously low oil level or some
other problem causing low oil
pressure. Check the vehicle's oil as
soon as possible. A DIC message
may display. See Engine Oil 0 350 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
146 Instruments and Controls When the engine is running, this
gauge shows the condition of the
charging system. The gauge can
transition from a higher to lower or a
lower to higher reading. This is
normal. If the vehicle is operating
outside the normal operating range,
the charging system light comes on.
See Charging System Light 0 149
for more information. The voltmeter
gauge may also read lower when in
fuel economy mode. This is normal.
Readings outside the normal
operating range can also occur
when a large number of electrical
accessories are operating in the
vehicle and the engine is left idling
for an extended period. This
condition is normal since the
charging system is not able to
provide full power at engine idle. As
engine speeds are increased, this
condition should correct itself as
higher engine speeds allow the
charging system to create maximum
power.
The vehicle can only be driven for a
short time with the readings outside
the normal operating range. If the vehicle must be driven, turn off all
accessories, such as the radio and
air conditioner and unplug all
chargers and accessories.
Readings outside the normal
operating range indicate a possible
problem in the electrical system.
Have the vehicle serviced as soon
as possible.
Seat Belt Reminders Driver Seat Belt Reminder
Light There is a driver seat belt reminder
light on the instrument cluster.
When the vehicle is started, this
light flashes and a chime may come
on to remind the driver to fasten
their seat belt. Then the light stays
on solid until the belt is buckled.
This cycle may continue several times if the driver remains or
becomes unbuckled while the
vehicle is moving.
If the driver seat belt is buckled,
neither the light nor the chime
comes on.
Passenger Seat Belt Reminder
Light There may be a passenger seat belt
reminder light near the passenger
airbag status indicator. See
Passenger Sensing System 0 86 .
For vehicles equipped with the
passenger seat belt reminder light,
when the vehicle is started this light
flashes and a chime may come on
to remind passengers to fasten their
seat belt. Then the light stays on
solid until the belt is buckled. This
cycle continues several times if the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 147passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger seat belt is
buckled, neither the chime nor the
light comes on.
The front passenger seat belt
reminder light and chime may turn
on if an object is put on the seat
such as a briefcase, handbag,
grocery bag, laptop, or other
electronic device. To turn off the
reminder light and/or chime, remove
the object from the seat or buckle
the seat belt.
Airbag Readiness Light This light shows if there is an
electrical problem with the airbag
system. The system check includes
the airbag sensor(s), passenger
sensing system (if equipped), the
pretensioners, the airbag modules,
the wiring, and the crash sensing
and diagnostic module. For more
information on the airbag system,
see Airbag System 0 77 . The airbag readiness light comes on
for several seconds when the
vehicle is started. If the light does
not come on then, have it fixed
immediately.
{ WarningIf the airbag readiness light stays
on after the vehicle is started or
comes on while driving, it means
the airbag system might not be
working properly. The airbags in
the vehicle might not inflate in a
crash, or they could even inflate
without a crash. To help avoid
injury, have the vehicle serviced
right away.
If there is a problem with the airbag
system, a Driver Information Center
(DIC) message may also come on. Airbag On-Off Light If the vehicle has an airbag on-off
switch, it also has a passenger
airbag status indicator located in the
overhead console.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
ON and OFF, or the symbol for on
and off, will light for several seconds
as a system check. Then, after
several more seconds, the status
indicator ON or OFF, or either the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
148 Instruments and Controls on or off symbol, will light to let you
know the status of the front
outboard passenger frontal airbag.
When the front outboard passenger
frontal airbag is manually turned off
using the airbag on-off switch on the
instrument panel endcap, the OFF
indicator light or the off symbol will
come on and stay on as a reminder
that the airbag has been turned off.
This light will go off when the airbag
has been turned on. See Airbag
On-Off Switch 0 84 for more
information, including important
safety information.
{ WarningIf the front outboard passenger
frontal airbag is turned off for a
person who is not in a risk group
identified by the national
government, that person will not
have the extra protection of an
airbag. In a crash, the airbag will
not be able to inflate and help
protect the person sitting there.
Do not turn off the front outboard
passenger frontal airbag unless
the person sitting there is in a risk
group identified by the national
government. See Airbag On-Off
Switch 0 84 for more information,
including important safety
information.
{ Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
(Continued) Warning (Continued) with the airbag system. For
example, the front outboard
passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
To help avoid injury to yourself or
others, have the vehicle serviced
right away. See Airbag Readiness
Light 0 147 for more information,
including important safety
information.
If the word ON or the on symbol is
lit, it means that the front outboard
passenger frontal airbag is enabled
(may inflate). See Airbag On-Off
Switch 0 84 for more information,
including important safety
information.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the airbag
on-off switch. See your dealer for
service.